基于应变设计X70管线钢管高强匹配环缝焊接性评估

High strength matching girth weldability evaluation for strain based design X70 linepipe

针对宝钢基于应变设计的大口径X70管线钢管,应用高强度和超高强度匹配焊接材料进行手工和半自动药芯焊丝气体保护环缝焊接,并对环焊接头进行拉伸、导向弯曲、低温冲击以及维氏硬度的检验与评估。结果表明,宝钢基于应变设计的X70管线钢管在手工焊接和半自动焊接条件下具有良好的环缝焊接性。采用超高强度匹配的铁粉低氢型焊条和气体保护金属粉芯焊丝,对钢管承受外部应变条件下焊接接头的安全性非常有利。

Manual shielded metal arc welding （SMAW）and semi-automatic gas metal arc welding（ GMAW）with flux cored wire have been conducted for large diameter strain based design X70 UOE linepipe of Baosteel, and furthermore, the girth welding joints have been evaluated including tensile, guided bending, low temperature impact toughness and Vickers hardness. As a result, the girth weldability of strain based design X70 UOE linepipe produced in Baosteel is excellent in the condition of SMAW and semi-automatic GMAW. It is greatly benefit for the safety of linepipe girth welding joint to endure the exterior strain when the super high strength matching ferrite powder low hydrogen electrode and gas shielded metal powder flux cored wire are applied.